#region License

/*
 * All content copyright Marko Lahma, unless otherwise indicated. All rights reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 */

#endregion

using Quartz.Spi;

namespace Quartz.Simpl;

/// <summary>
/// The default InstanceIdGenerator used by Quartz when instance id is to be
/// automatically generated.  Instance id is of the form HOSTNAME + CURRENT_TIME.
/// </summary>
/// <author>Marko Lahma (.NET)</author>
/// <seealso cref="IInstanceIdGenerator" />
/// <seealso cref="HostnameInstanceIdGenerator" />
internal sealed class SimpleInstanceIdGenerator : HostNameBasedIdGenerator
{
    // assume ticks to be at most 20 chars long
    private const int HostNameMaxLength = IdMaxLength - 20;

    /// <summary>
    /// Generate the instance id for a <see cref="IScheduler" />
    /// </summary>
    /// <param name="cancellationToken"></param>
    /// <returns>The clusterwide unique instance id.</returns>
    public override async ValueTask<string?> GenerateInstanceId(CancellationToken cancellationToken = default)
    {
        var hostName = await GetHostName(HostNameMaxLength, cancellationToken).ConfigureAwait(false);
        return hostName + SystemTime.UtcNow().Ticks;
    }
}